@Trixie: I get the guilts about using Amazon at all and filter to make sure I order from a trader with a good rating.
Amazon still gets a healthy cut when you buy through an independent retailer on the Amazon marketplace. Arguably for doing less than if they sell the thing themselves.
What I often do is find the item on the Amazon marketplace, then Google the retailer's own web site to see if their price there is as good. It's a bit like choosing the product you want in a local, physical shop, and then going online to get it cheaper (I think that's called "showcasing"?) Only in reverse.
If the price on the retailer's own web site is higher than their marketplace price then I assume that they're happy to pay Amazon their cut, and order through Amazon. Otherwise I order direct. The consumer contracts regulations give you pretty good legal protection on all online transactions these days (although it has to be said that Amazon's customer service is still usually better than most independent retailers).
The only time I use Amazon Prime is when they are running a free trial promotion. Even then I cancel as soon as the trial is up and running (the free Prime service continues to the end of the trial period then stops).
For retailers like Wiggle/CRC and Evans, try signing up with Quidco to get cashback on online orders. (Likely the other cashback providers also cover those retailers.) Quidco do cover Halfords, but the 10% in-store* discount with British Cycling or AA membership is more worthwhile.
* AIUI you can't use that discount for a fully online order i.e. one that is going to be delivered to you, you can place the order online as a click & collect - which is free - and get the discount when you pay on collection.